jQuery.extend({
	    handleError : function(s, xhr, status, e) {
		    // If a local callback was specified, fire it   
		    if (s.error) {
			    s.error.call(s.context || s, xhr, status, e);
		    }

		    // Fire the global callback   
		    if (s.global) {
			    (s.context ? jQuery(s.context) : jQuery.event).trigger("ajaxError", [xhr, s, e]);
		    }
	    },

	    createUploadIframe : function(id, uri) {
		    //create frame
		    var frameId = 'jUploadFrame' + id;
		    var iframeHtml = '<iframe id="' + frameId + '" name="' + frameId
		        + '" style="position:absolute; top:-9999px; left:-9999px"';
		    if (window.ActiveXObject) {
			    if (typeof uri == 'boolean') {
				    iframeHtml += ' src="' + 'javascript:false' + '"';
			    } else if (typeof uri == 'string') {
				    iframeHtml += ' src="' + uri + '"';
			    }
		    }
		    iframeHtml += ' />';
		    jQuery(iframeHtml).appendTo(document.body);
		    return jQuery('#' + frameId).get(0);
	    },
	    
	    createUploadForm : function(id, fileElementId, data) {
		    //create form	
		    var formId = 'jUploadForm' + id;
		    var fileId = 'jUploadFile' + id;
		    var form = jQuery('<form  action="" method="POST" name="' + formId + '" id="' + formId
		        + '" enctype="multipart/form-data"></form>');
		    if (data) {
			    for (var i in data) {
				    jQuery('<input type="hidden" name="' + i + '" value="' + data[i] + '" />')
				        .appendTo(form);
			    }
		    }
		    var oldElement = jQuery('#' + fileElementId);
		    var newElement = jQuery(oldElement).clone();
		    jQuery(oldElement).attr('id', fileId);
		    jQuery(oldElement).before(newElement);
		    jQuery(oldElement).appendTo(form);

		    //set attributes
		    jQuery(form).css('position', 'absolute');
		    jQuery(form).css('top', '-1200px');
		    jQuery(form).css('left', '-1200px');
		    jQuery(form).appendTo('body');
		    return form;
	    },

	    ajaxFileUpload : function(s) {
		    // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout		
		    s = jQuery.extend({}, jQuery.ajaxSettings, s);
		    var id = new Date().getTime()
		    var form = jQuery.createUploadForm(id, s.fileElementId, (typeof(s.data) == 'undefined'
		            ? false
		            : s.data));
		    var io = jQuery.createUploadIframe(id, s.secureuri);
		    var frameId = 'jUploadFrame' + id;
		    var formId = 'jUploadForm' + id;
		    // Watch for a new set of requests
		    if (s.global && !jQuery.active++) {
			    jQuery.event.trigger("ajaxStart");
		    }
		    var requestDone = false;
		    // Create the request object
		    var xml = {}
		    if (s.global)
			    jQuery.event.trigger("ajaxSend", [xml, s]);
		    // Wait for a response to come back
		    var uploadCallback = function(isTimeout) {
			    var io = document.getElementById(frameId);
			    try {
				    if (io.contentWindow) {
					    xml.responseText = io.contentWindow.document.body
					        ? io.contentWindow.document.body.innerHTML
					        : null;
					    xml.responseXML = io.contentWindow.document.XMLDocument
					        ? io.contentWindow.document.XMLDocument
					        : io.contentWindow.document;
				    } else if (io.contentDocument) {
					    xml.responseText = io.contentDocument.document.body
					        ? io.contentDocument.document.body.innerHTML
					        : null;
					    xml.responseXML = io.contentDocument.document.XMLDocument
					        ? io.contentDocument.document.XMLDocument
					        : io.contentDocument.document;
				    }
			    } catch (e) {
				    jQuery.handleError(s, xml, null, e);
			    }
			    if (xml || isTimeout == "timeout") {
				    requestDone = true;
				    var status;
				    try {
					    status = isTimeout != "timeout" ? "success" : "error";
					    // Make sure that the request was successful or notmodified
					    if (status != "error") {
						    // process the data (runs the xml through httpData regardless of callback)
						    var data = jQuery.uploadHttpData(xml, s.dataType);
						    // If a local callback was specified, fire it and pass it the data
						    if (s.success)
							    s.success(data, status);
						    // Fire the global callback
						    if (s.global)
							    jQuery.event.trigger("ajaxSuccess", [xml, s]);
					    } else
						    jQuery.handleError(s, xml, status);
				    } catch (e) {
					    status = "error";
					    jQuery.handleError(s, xml, status, e);
				    }

				    // The request was completed
				    if (s.global)
					    jQuery.event.trigger("ajaxComplete", [xml, s]);

				    // Handle the global AJAX counter
				    if (s.global && !--jQuery.active)
					    jQuery.event.trigger("ajaxStop");

				    // Process result
				    if (s.complete)
					    s.complete(xml, status);

				    jQuery(io).unbind()

				    setTimeout(function() {
					        try {
						        jQuery(io).remove();
						        jQuery(form).remove();

					        } catch (e) {
						        jQuery.handleError(s, xml, null, e);
					        }

				        }, 100)

				    xml = null

			    }
		    }
		    // Timeout checker
		    if (s.timeout > 0) {
			    setTimeout(function() {
				        // Check to see if the request is still happening
				        if (!requestDone)
					        uploadCallback("timeout");
			        }, s.timeout);
		    }
		    try {
			    var form = jQuery('#' + formId);
			    jQuery(form).attr('action', s.url);
			    jQuery(form).attr('method', 'POST');
			    jQuery(form).attr('target', frameId);
			    if (form.encoding) {
				    jQuery(form).attr('encoding', 'multipart/form-data');
			    } else {
				    jQuery(form).attr('enctype', 'multipart/form-data');
			    }
			    jQuery(form).submit();

		    } catch (e) {
			    jQuery.handleError(s, xml, null, e);
		    }

		    jQuery('#' + frameId).load(uploadCallback);
		    return {
			    abort : function() {
			    }
		    };
	    },

	    uploadHttpData : function(r, type) {
		    var data = !type;
		    data = type == "xml" || data ? r.responseXML : r.responseText;
		    // If the type is "script", eval it in global context
		    if (type == "script")
			    jQuery.globalEval(data);
		    // Get the JavaScript object, if JSON is used.
		    if (type == "json")
			    eval("data = " + data);
		    // evaluate scripts within html
		    if (type == "html")
			    jQuery("<div>").html(data).evalScripts();

		    return data;
	    }
    })
